Atomic structure and isotopes

Question 1

relative charge of neutron

Answer 1

0

Question 2

relative charge of proton

Answer 2

+1

Question 3

relative charge of electron

Answer 3

-1

Question 4

relative mass of protons and neutrons

Answer 4

both 1

Question 5

relative mass of electrons

Answer 5

1/1836

Question 6

to work out mass number…

Answer 6

no of protons + no of neutrons

Question 7

atomic number =

Answer 7

no of protons

Question 8

what are ions

Answer 8

atoms that have gained or lost e- to become charged particles

Question 9

define isotope

Answer 9

atoms of the same element that have the same number of protons but different number of neutrons, so have different mass numbers

Question 10

why do isotopes react in similar ways

Answer 10

same no of e- in outer shell and same electron configuration

Question 11

do isotopes have the same physical properties

Answer 11

may be different

Question 12

define relative isotopic mass
(not weighted mean)

Answer 12

mass of an isotope compared with 1/12th mass of carbon-12

Question 13

define relative atomic mass, Ar

Answer 13

Weighted mean mass of an atom of an element compared with 1/12th mass of carbon-12

Question 14

define relative molecular mass, Mr

Answer 14

weighted mean mass of one molecule of a substance relative to 1/12th mass of carbon-12

Question 15

what’s mass SPECTROMETRY used for

Answer 15

• to accurately measure the relative isotopic mass
• abundance of each isotope of an element present in the sample measured so Ar can be calculated
• elements can be identified

Question 16

what’s m/z

Answer 16

• mass/charge
• ratio normally = relative isotopic mass as the charge on ion is 1+

Question 17

equation to work out atomic mass, Ar

Answer 17

Ar = (mass x %) + ( mass x %) / 100